I've built my own GIMX with an Arduino Micro 32U4 and a USB CP2102.
I am emulating my G25 to a G29. (brass optical encoder)
I've flashed the Arduino successfully and installed the default settings for LogitechG25_G29.xml
I can start the GIMX launcher (Win7 64bit) and everything works fine.
The PS4 recognizes my G25 as a G29. Perfect!

Now what is the problem:
After a few minutes of racing GT Sport , suddenly I have no throttle, brake or the steering wheel.
Even all the other buttons stopped working.
There is still the force feedback working but the game does not identify it.
Meanwhile, the car is driving with the last input (for example accelerating out of a curve)

The main problem is I don't get any feedback from the GIMX launcher.
It says that everything is still O.K. (no error report).

My current solution is to unplug everything and to restart GIMX launcher.
After 5-15 minutes the error appears again.
Can anybody help me?